A trilogy of films could be made after the forthcoming fifth series of Merlin, it has been revealed.

According to a report on Digital Spy, show co-creator Johnny Capps told this year's San Diego Comic-Con:

We're hopefully going to do a trilogy - three movies. We will focus on them when we finish season five.

One idea we've been playing around with is to reboot the whole series [for the films]. We would go back in time and start the story again and show different parts that you didn't see in the series. The other idea is to do a continuation, but we haven't decided yet.

A promotional picture for Series 5 was also released at Comic-Con. Pictured right, it features Colin Morgan (Merlin), Angel Coulby (Guinevere/Gwen), Katie McGrath (Morgana), Bradley James (King Arthur), and Richard Wilson (Gaius), with the subhead "The Die Is Cast". Click on the image to enlarge it.

The new series, comprising 13 episodes, started filming in March and returns to BBC One later in the year. According to a tweet on the official Merlin Twitter account, Capps also revealed that Anthony Head will guest-star in a reprise of his role as Uther Pendragon in the fifth series. Liam Cunningham and John Bradley have also been cast. In addition, Lindsay Duncan and Janet Montgomery will be returning as Queen Annis and Princess Mithian respectively.

An official YouTube channel for the programme has also been launched, featuring trailers, promos, interviews, and various looks behind the scenes.